A power supply device using a secondary battery has been used for a power supply for driving a vehicle, for example. Such a power supply device generally has a configuration as shown in an exploded perspective view of FIG. 11. In FIG. 11, plural sheets of secondary battery cells 901 are stacked, and both ends thereof are covered with end plates 903, and then end plates 903 are fastened each other by right and left binding bars which are a pair of binding bars in each of right and left (for example, Patent Literature 1). When the output is increased, in such power supply device 900, it is thought that the number of secondary battery cells 901 is increased.
However, in the configuration where end plates 903 and the binding bars as mentioned above, when the number of secondary battery cells 901 is increased, the length of the module becomes long. Then, in response to this, the increase of the hardness is required. For example, as shown in FIG. 12A, FIG. 12B, when stress is added to the side surface of the battery stacked body, load is exerted to the binding bars at one side. Then, in order to correspond to this, it is necessary to increase hardness of the binding bars. Accordingly, countermeasures are required where a metal board constituting the binding bar is made thick, or strong material of the binding bar is used. As a result, problems in which the weight or cost is increased occur. Also, as the number of the secondary battery cells increase, misalignment of the battery cells located at the center may occur largely. Further, since the thickness of the secondary battery cell includes manufacturing allowance, when the number of the secondary battery cells is increased, dispersion of the thicknesses of the cells is accumulated as shown in FIG. 15. Then, countermeasure for absorbing this is necessary.
On the other hand, as shown in FIG. 13, FIG. 14, in power supply device 800 relating to Patent Literature 1, several section boards are disposed between end plates 803, and fixing points of the module are increased by bolts for fastening which pass through the section boards. This structure suppresses misalignment of the battery cells.
However, in the above-mentioned configuration, since load caused by the section boards is applied to the rods for fastening in a shearing direction, the rods for fastening may be damaged.